I build a couple of bottomless cedar planters/raised beds last spring to replace a row of plasticky grow-bags where I grow pole beans up our catio walls.
I selected these boards because they were at Home Depot on deep discount for being slightly warped. I ended up having to man-handle and overscrew them into shape, but it was totally worth it. I would rather they have been wider, for a deeper bed but you can't argue with 70% off.
I got five boards, so each planter/bed was made eight feet long and just over one foot wide. I chopped one board into eight ~1' lengths and used four as spacers and fastening points. I clamped them up to hold the short board in place for creating the pilot holes and holding them still and stable until the screws were in. And I just went down the line. Getting the last insert in place was the hardest bit, not rocket science.
This is the first one done:
And then they're both done:
Just to include a picture of them in place, I went and snapped one just now. I grew pole beans, beet greens, and potatoes this year, plus some black nightshade volunteered.
If it helps for judging, my best guess from the pictures' timestamps puts this job at just over 3 hours for me -- someone with a shop set up would have been faster.